Solve Equations by Substitution

6.AF.4

Understand that solving an equation or inequality is the process of answering the following question: Which values from a specified set, if any, make the equation or inequality true? Use substitution to determine whether a given number in a specified set makes an equation or inequality true.

6.AF.2

Apply the properties of operations (e.g., identity, inverse, commutative, associative, distributive properties) to create equivalent linear expressions and to justify whether two linear expressions are equivalent when the two expressions name the same number regardless of which value is substituted into them.

Variable = a letter or symbol that represents an unknown or changing number or value

Equation: a number sentence that indicates that two expressions are equal

Solution: a value of a variable that makes an equation true

Replacement set: the given set of numbers that a variable may represent

Solution set: the set of all solutions to a given open sentence